BACKTEST · CALENDAR
Turn-of-the-month effect
SPY bought from the 26th, sold from the 4th of the next month.
From 2015-01-02 to 2024-12-31, this rule made 120 trades and returned +109.1%. Buying and holding SPY returned +185.3% over the same dates. The largest drop from a past high was 9.9%.
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The rule
SPY bought from the 26th, sold from the 4th of the next month. Orders fill at the next close.
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Did it beat SPY?
How it did over time
Strategy in orange-red. SPY buy and hold in light.
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The same result in an AI chat
This is how the result looks when an AI agent such as Claude or ChatGPT runs it. It uses the same engine report.
Strategy equity in orange-red, SPY in light. Historical test only.
Every trade
120 trades and 239 fills, straight from the engine report. Each fill shows the day the signal fired, the day it filled, and why. This run used 0 bps fees and 0 bps slippage on each fill, except when a modeled option expires. A basis point (bps) is one hundredth of one percent.
| Signal date | Fill date | Ticker | Side | Price | Reason |
|---|---|---|---|---|---|
| 2015-01-26 | 2015-01-27 | SPY | Buy | $202.74 | entry |
| 2015-02-04 | 2015-02-05 | SPY | Sell | $206.12 | exit |
| 2015-02-26 | 2015-02-27 | SPY | Buy | $210.66 | entry |
| 2015-03-04 | 2015-03-05 | SPY | Sell | $210.46 | exit |
| 2015-03-26 | 2015-03-27 | SPY | Buy | $205.74 | entry |
| 2015-04-06 | 2015-04-07 | SPY | Sell | $207.28 | exit |
| 2015-04-27 | 2015-04-28 | SPY | Buy | $211.44 | entry |
| 2015-05-04 | 2015-05-05 | SPY | Sell | $208.90 | exit |
| 2015-05-26 | 2015-05-27 | SPY | Buy | $212.70 | entry |
| 2015-06-04 | 2015-06-05 | SPY | Sell | $209.77 | exit |
| 2015-06-26 | 2015-06-29 | SPY | Buy | $205.47 | entry |
| 2015-07-06 | 2015-07-07 | SPY | Sell | $208.01 | exit |
| 2015-07-27 | 2015-07-28 | SPY | Buy | $209.31 | entry |
| 2015-08-04 | 2015-08-05 | SPY | Sell | $210.10 | exit |
| 2015-08-26 | 2015-08-27 | SPY | Buy | $199.16 | entry |
| 2015-09-04 | 2015-09-08 | SPY | Sell | $197.46 | exit |
| 2015-09-28 | 2015-09-29 | SPY | Buy | $188.08 | entry |
| 2015-10-05 | 2015-10-06 | SPY | Sell | $197.79 | exit |
| 2015-10-26 | 2015-10-27 | SPY | Buy | $206.57 | entry |
| 2015-11-04 | 2015-11-05 | SPY | Sell | $210.15 | exit |
| 2015-11-27 | 2015-11-30 | SPY | Buy | $208.69 | entry |
| 2015-12-04 | 2015-12-07 | SPY | Sell | $208.35 | exit |
| 2015-12-28 | 2015-12-29 | SPY | Buy | $207.40 | entry |
| 2016-01-04 | 2016-01-05 | SPY | Sell | $201.36 | exit |
| 2016-01-26 | 2016-01-27 | SPY | Buy | $188.13 | entry |
| 2016-02-04 | 2016-02-05 | SPY | Sell | $187.95 | exit |
| 2016-02-26 | 2016-02-29 | SPY | Buy | $193.56 | entry |
| 2016-03-04 | 2016-03-07 | SPY | Sell | $200.59 | exit |
| 2016-03-28 | 2016-03-29 | SPY | Buy | $205.12 | entry |
| 2016-04-04 | 2016-04-05 | SPY | Sell | $204.19 | exit |
| 2016-04-26 | 2016-04-27 | SPY | Buy | $209.35 | entry |
| 2016-05-04 | 2016-05-05 | SPY | Sell | $204.97 | exit |
| 2016-05-26 | 2016-05-27 | SPY | Buy | $210.24 | entry |
| 2016-06-06 | 2016-06-07 | SPY | Sell | $211.68 | exit |
| 2016-06-27 | 2016-06-28 | SPY | Buy | $203.20 | entry |
| 2016-07-05 | 2016-07-06 | SPY | Sell | $209.66 | exit |
| 2016-07-26 | 2016-07-27 | SPY | Buy | $216.52 | entry |
| 2016-08-04 | 2016-08-05 | SPY | Sell | $218.18 | exit |
| 2016-08-26 | 2016-08-29 | SPY | Buy | $218.36 | entry |
| 2016-09-06 | 2016-09-07 | SPY | Sell | $219.01 | exit |
Show all 239 fills
| Signal date | Fill date | Ticker | Side | Price | Reason |
|---|---|---|---|---|---|
| 2016-09-26 | 2016-09-27 | SPY | Buy | $215.57 | entry |
| 2016-10-04 | 2016-10-05 | SPY | Sell | $215.63 | exit |
| 2016-10-26 | 2016-10-27 | SPY | Buy | $213.17 | entry |
| 2016-11-04 | 2016-11-07 | SPY | Sell | $213.15 | exit |
| 2016-11-28 | 2016-11-29 | SPY | Buy | $220.91 | entry |
| 2016-12-05 | 2016-12-06 | SPY | Sell | $221.70 | exit |
| 2016-12-27 | 2016-12-28 | SPY | Buy | $224.40 | entry |
| 2017-01-04 | 2017-01-05 | SPY | Sell | $226.40 | exit |
| 2017-01-26 | 2017-01-27 | SPY | Buy | $228.97 | entry |
| 2017-02-06 | 2017-02-07 | SPY | Sell | $228.94 | exit |
| 2017-02-27 | 2017-02-28 | SPY | Buy | $236.47 | entry |
| 2017-03-06 | 2017-03-07 | SPY | Sell | $237.00 | exit |
| 2017-03-27 | 2017-03-28 | SPY | Buy | $235.32 | entry |
| 2017-04-04 | 2017-04-05 | SPY | Sell | $234.78 | exit |
| 2017-04-26 | 2017-04-27 | SPY | Buy | $238.60 | entry |
| 2017-05-04 | 2017-05-05 | SPY | Sell | $239.70 | exit |
| 2017-05-26 | 2017-05-30 | SPY | Buy | $241.50 | entry |
| 2017-06-05 | 2017-06-06 | SPY | Sell | $243.21 | exit |
| 2017-06-26 | 2017-06-27 | SPY | Buy | $241.33 | entry |
| 2017-07-05 | 2017-07-06 | SPY | Sell | $240.55 | exit |
| 2017-07-26 | 2017-07-27 | SPY | Buy | $247.20 | entry |
| 2017-08-04 | 2017-08-07 | SPY | Sell | $247.87 | exit |
| 2017-08-28 | 2017-08-29 | SPY | Buy | $244.85 | entry |
| 2017-09-05 | 2017-09-06 | SPY | Sell | $246.90 | exit |
| 2017-09-26 | 2017-09-27 | SPY | Buy | $250.05 | entry |
| 2017-10-04 | 2017-10-05 | SPY | Sell | $254.66 | exit |
| 2017-10-26 | 2017-10-27 | SPY | Buy | $257.71 | entry |
| 2017-11-06 | 2017-11-07 | SPY | Sell | $258.67 | exit |
| 2017-11-27 | 2017-11-28 | SPY | Buy | $262.87 | entry |
| 2017-12-04 | 2017-12-05 | SPY | Sell | $263.19 | exit |
| 2017-12-26 | 2017-12-27 | SPY | Buy | $267.32 | entry |
| 2018-01-04 | 2018-01-05 | SPY | Sell | $273.42 | exit |
| 2018-01-26 | 2018-01-29 | SPY | Buy | $284.68 | entry |
| 2018-02-05 | 2018-02-06 | SPY | Sell | $269.13 | exit |
| 2018-02-26 | 2018-02-27 | SPY | Buy | $274.43 | entry |
| 2018-03-05 | 2018-03-06 | SPY | Sell | $272.88 | exit |
| 2018-03-26 | 2018-03-27 | SPY | Buy | $260.60 | entry |
| 2018-04-04 | 2018-04-05 | SPY | Sell | $265.64 | exit |
| 2018-04-26 | 2018-04-27 | SPY | Buy | $266.56 | entry |
| 2018-05-04 | 2018-05-07 | SPY | Sell | $266.92 | exit |
| 2018-05-29 | 2018-05-30 | SPY | Buy | $272.61 | entry |
| 2018-06-04 | 2018-06-05 | SPY | Sell | $275.10 | exit |
| 2018-06-26 | 2018-06-27 | SPY | Buy | $269.35 | entry |
| 2018-07-05 | 2018-07-06 | SPY | Sell | $275.42 | exit |
| 2018-07-26 | 2018-07-27 | SPY | Buy | $281.42 | entry |
| 2018-08-06 | 2018-08-07 | SPY | Sell | $285.58 | exit |
| 2018-08-27 | 2018-08-28 | SPY | Buy | $289.92 | entry |
| 2018-09-04 | 2018-09-05 | SPY | Sell | $289.03 | exit |
| 2018-09-26 | 2018-09-27 | SPY | Buy | $290.69 | entry |
| 2018-10-04 | 2018-10-05 | SPY | Sell | $287.82 | exit |
| 2018-10-26 | 2018-10-29 | SPY | Buy | $263.86 | entry |
| 2018-11-05 | 2018-11-06 | SPY | Sell | $275.12 | exit |
| 2018-11-26 | 2018-11-27 | SPY | Buy | $268.40 | entry |
| 2018-12-04 | 2018-12-06 | SPY | Sell | $269.84 | exit |
| 2018-12-26 | 2018-12-27 | SPY | Buy | $248.07 | entry |
| 2019-01-04 | 2019-01-07 | SPY | Sell | $254.38 | exit |
| 2019-01-28 | 2019-01-29 | SPY | Buy | $263.41 | entry |
| 2019-02-04 | 2019-02-05 | SPY | Sell | $273.10 | exit |
| 2019-02-26 | 2019-02-27 | SPY | Buy | $279.20 | entry |
| 2019-03-04 | 2019-03-05 | SPY | Sell | $279.02 | exit |
| 2019-03-26 | 2019-03-27 | SPY | Buy | $279.65 | entry |
| 2019-04-04 | 2019-04-05 | SPY | Sell | $288.57 | exit |
| 2019-04-26 | 2019-04-29 | SPY | Buy | $293.87 | entry |
| 2019-05-06 | 2019-05-07 | SPY | Sell | $287.93 | exit |
| 2019-05-28 | 2019-05-29 | SPY | Buy | $278.27 | entry |
| 2019-06-04 | 2019-06-05 | SPY | Sell | $282.96 | exit |
| 2019-06-26 | 2019-06-27 | SPY | Buy | $291.50 | entry |
| 2019-07-05 | 2019-07-08 | SPY | Sell | $296.82 | exit |
| 2019-07-26 | 2019-07-29 | SPY | Buy | $301.46 | entry |
| 2019-08-05 | 2019-08-06 | SPY | Sell | $287.80 | exit |
| 2019-08-26 | 2019-08-27 | SPY | Buy | $286.87 | entry |
| 2019-09-04 | 2019-09-05 | SPY | Sell | $297.82 | exit |
| 2019-09-26 | 2019-09-27 | SPY | Buy | $295.40 | entry |
| 2019-10-04 | 2019-10-07 | SPY | Sell | $293.08 | exit |
| 2019-10-28 | 2019-10-29 | SPY | Buy | $303.21 | entry |
| 2019-11-04 | 2019-11-05 | SPY | Sell | $307.03 | exit |
| 2019-11-26 | 2019-11-27 | SPY | Buy | $315.48 | entry |
| 2019-12-04 | 2019-12-05 | SPY | Sell | $312.02 | exit |
| 2019-12-26 | 2019-12-27 | SPY | Buy | $322.86 | entry |
| 2020-01-06 | 2020-01-07 | SPY | Sell | $322.73 | exit |
| 2020-01-27 | 2020-01-28 | SPY | Buy | $326.89 | entry |
| 2020-02-04 | 2020-02-05 | SPY | Sell | $332.86 | exit |
| 2020-02-26 | 2020-02-27 | SPY | Buy | $297.51 | entry |
| 2020-03-04 | 2020-03-05 | SPY | Sell | $302.46 | exit |
| 2020-03-26 | 2020-03-27 | SPY | Buy | $253.42 | entry |
| 2020-04-06 | 2020-04-07 | SPY | Sell | $265.13 | exit |
| 2020-04-27 | 2020-04-28 | SPY | Buy | $285.73 | entry |
| 2020-05-04 | 2020-05-05 | SPY | Sell | $286.19 | exit |
| 2020-05-26 | 2020-05-27 | SPY | Buy | $303.53 | entry |
| 2020-06-04 | 2020-06-05 | SPY | Sell | $319.34 | exit |
| 2020-06-26 | 2020-06-29 | SPY | Buy | $304.46 | entry |
| 2020-07-06 | 2020-07-07 | SPY | Sell | $313.78 | exit |
| 2020-07-27 | 2020-07-28 | SPY | Buy | $321.17 | entry |
| 2020-08-04 | 2020-08-05 | SPY | Sell | $332.11 | exit |
| 2020-08-26 | 2020-08-27 | SPY | Buy | $348.33 | entry |
| 2020-09-04 | 2020-09-08 | SPY | Sell | $333.21 | exit |
| 2020-09-28 | 2020-09-29 | SPY | Buy | $332.37 | entry |
| 2020-10-05 | 2020-10-06 | SPY | Sell | $334.93 | exit |
| 2020-10-26 | 2020-10-27 | SPY | Buy | $338.22 | entry |
| 2020-11-04 | 2020-11-05 | SPY | Sell | $350.24 | exit |
| 2020-11-27 | 2020-11-30 | SPY | Buy | $362.06 | entry |
| 2020-12-04 | 2020-12-07 | SPY | Sell | $369.09 | exit |
| 2020-12-28 | 2020-12-29 | SPY | Buy | $371.46 | entry |
| 2021-01-04 | 2021-01-05 | SPY | Sell | $371.33 | exit |
| 2021-01-26 | 2021-01-27 | SPY | Buy | $374.41 | entry |
| 2021-02-04 | 2021-02-05 | SPY | Sell | $387.71 | exit |
| 2021-02-26 | 2021-03-01 | SPY | Buy | $389.58 | entry |
| 2021-03-04 | 2021-03-05 | SPY | Sell | $383.63 | exit |
| 2021-03-26 | 2021-03-29 | SPY | Buy | $395.78 | entry |
| 2021-04-05 | 2021-04-06 | SPY | Sell | $406.12 | exit |
| 2021-04-26 | 2021-04-27 | SPY | Buy | $417.52 | entry |
| 2021-05-04 | 2021-05-05 | SPY | Sell | $415.75 | exit |
| 2021-05-26 | 2021-05-27 | SPY | Buy | $419.29 | entry |
| 2021-06-04 | 2021-06-07 | SPY | Sell | $422.19 | exit |
| 2021-06-28 | 2021-06-29 | SPY | Buy | $427.70 | entry |
| 2021-07-06 | 2021-07-07 | SPY | Sell | $434.46 | exit |
| 2021-07-26 | 2021-07-27 | SPY | Buy | $439.01 | entry |
| 2021-08-04 | 2021-08-05 | SPY | Sell | $441.76 | exit |
| 2021-08-26 | 2021-08-27 | SPY | Buy | $450.25 | entry |
| 2021-09-07 | 2021-09-08 | SPY | Sell | $450.91 | exit |
| 2021-09-27 | 2021-09-28 | SPY | Buy | $433.72 | entry |
| 2021-10-04 | 2021-10-05 | SPY | Sell | $433.10 | exit |
| 2021-10-26 | 2021-10-27 | SPY | Buy | $453.94 | entry |
| 2021-11-04 | 2021-11-05 | SPY | Sell | $468.53 | exit |
| 2021-11-26 | 2021-11-29 | SPY | Buy | $464.60 | entry |
| 2021-12-06 | 2021-12-07 | SPY | Sell | $468.28 | exit |
| 2021-12-27 | 2021-12-28 | SPY | Buy | $476.87 | entry |
| 2022-01-04 | 2022-01-05 | SPY | Sell | $468.38 | exit |
| 2022-01-26 | 2022-01-27 | SPY | Buy | $431.24 | entry |
| 2022-02-04 | 2022-02-07 | SPY | Sell | $447.26 | exit |
| 2022-02-28 | 2022-03-01 | SPY | Buy | $429.98 | entry |
| 2022-03-04 | 2022-03-07 | SPY | Sell | $419.43 | exit |
| 2022-03-28 | 2022-03-29 | SPY | Buy | $461.55 | entry |
| 2022-04-04 | 2022-04-05 | SPY | Sell | $451.03 | exit |
| 2022-04-26 | 2022-04-27 | SPY | Buy | $417.27 | entry |
| 2022-05-04 | 2022-05-05 | SPY | Sell | $413.81 | exit |
| 2022-05-26 | 2022-05-27 | SPY | Buy | $415.26 | entry |
| 2022-06-06 | 2022-06-07 | SPY | Sell | $415.74 | exit |
| 2022-06-27 | 2022-06-28 | SPY | Buy | $380.65 | entry |
| 2022-07-05 | 2022-07-06 | SPY | Sell | $383.25 | exit |
| 2022-07-26 | 2022-07-27 | SPY | Buy | $401.04 | entry |
| 2022-08-04 | 2022-08-05 | SPY | Sell | $413.47 | exit |
| 2022-08-26 | 2022-08-29 | SPY | Buy | $402.63 | entry |
| 2022-09-06 | 2022-09-07 | SPY | Sell | $397.78 | exit |
| 2022-09-26 | 2022-09-27 | SPY | Buy | $363.38 | entry |
| 2022-10-04 | 2022-10-05 | SPY | Sell | $377.09 | exit |
| 2022-10-26 | 2022-10-27 | SPY | Buy | $379.98 | entry |
| 2022-11-04 | 2022-11-07 | SPY | Sell | $379.95 | exit |
| 2022-11-28 | 2022-11-29 | SPY | Buy | $395.23 | entry |
| 2022-12-05 | 2022-12-06 | SPY | Sell | $393.83 | exit |
| 2022-12-27 | 2022-12-28 | SPY | Buy | $376.66 | entry |
| 2023-01-04 | 2023-01-05 | SPY | Sell | $379.38 | exit |
| 2023-01-26 | 2023-01-27 | SPY | Buy | $405.68 | entry |
| 2023-02-06 | 2023-02-07 | SPY | Sell | $415.19 | exit |
| 2023-02-27 | 2023-02-28 | SPY | Buy | $396.26 | entry |
| 2023-03-06 | 2023-03-07 | SPY | Sell | $398.27 | exit |
| 2023-03-27 | 2023-03-28 | SPY | Buy | $395.60 | entry |
| 2023-04-04 | 2023-04-05 | SPY | Sell | $407.60 | exit |
| 2023-04-26 | 2023-04-27 | SPY | Buy | $412.41 | entry |
| 2023-05-04 | 2023-05-05 | SPY | Sell | $412.63 | exit |
| 2023-05-26 | 2023-05-30 | SPY | Buy | $420.18 | entry |
| 2023-06-05 | 2023-06-06 | SPY | Sell | $428.03 | exit |
| 2023-06-26 | 2023-06-27 | SPY | Buy | $436.17 | entry |
| 2023-07-05 | 2023-07-06 | SPY | Sell | $439.66 | exit |
| 2023-07-26 | 2023-07-27 | SPY | Buy | $452.49 | entry |
| 2023-08-04 | 2023-08-07 | SPY | Sell | $450.71 | exit |
| 2023-08-28 | 2023-08-29 | SPY | Buy | $449.16 | entry |
| 2023-09-05 | 2023-09-06 | SPY | Sell | $446.22 | exit |
| 2023-09-26 | 2023-09-27 | SPY | Buy | $426.05 | entry |
| 2023-10-04 | 2023-10-05 | SPY | Sell | $424.50 | exit |
| 2023-10-26 | 2023-10-27 | SPY | Buy | $410.68 | entry |
| 2023-11-06 | 2023-11-07 | SPY | Sell | $436.93 | exit |
| 2023-11-27 | 2023-11-28 | SPY | Buy | $454.93 | entry |
| 2023-12-04 | 2023-12-05 | SPY | Sell | $456.60 | exit |
| 2023-12-26 | 2023-12-27 | SPY | Buy | $476.51 | entry |
| 2024-01-04 | 2024-01-05 | SPY | Sell | $467.92 | exit |
| 2024-01-26 | 2024-01-29 | SPY | Buy | $491.27 | entry |
| 2024-02-05 | 2024-02-06 | SPY | Sell | $493.98 | exit |
| 2024-02-26 | 2024-02-27 | SPY | Buy | $506.93 | entry |
| 2024-03-04 | 2024-03-05 | SPY | Sell | $507.18 | exit |
| 2024-03-26 | 2024-03-27 | SPY | Buy | $523.17 | entry |
| 2024-04-04 | 2024-04-05 | SPY | Sell | $518.43 | exit |
| 2024-04-26 | 2024-04-29 | SPY | Buy | $510.06 | entry |
| 2024-05-06 | 2024-05-07 | SPY | Sell | $517.14 | exit |
| 2024-05-28 | 2024-05-29 | SPY | Buy | $526.10 | entry |
| 2024-06-04 | 2024-06-05 | SPY | Sell | $534.67 | exit |
| 2024-06-26 | 2024-06-27 | SPY | Buy | $546.37 | entry |
| 2024-07-05 | 2024-07-08 | SPY | Sell | $555.28 | exit |
| 2024-07-26 | 2024-07-29 | SPY | Buy | $544.76 | entry |
| 2024-08-05 | 2024-08-06 | SPY | Sell | $522.15 | exit |
| 2024-08-26 | 2024-08-27 | SPY | Buy | $561.56 | entry |
| 2024-09-04 | 2024-09-05 | SPY | Sell | $549.61 | exit |
| 2024-09-26 | 2024-09-27 | SPY | Buy | $571.47 | entry |
| 2024-10-04 | 2024-10-07 | SPY | Sell | $567.80 | exit |
| 2024-10-28 | 2024-10-29 | SPY | Buy | $581.77 | entry |
| 2024-11-04 | 2024-11-05 | SPY | Sell | $576.70 | exit |
| 2024-11-26 | 2024-11-27 | SPY | Buy | $598.83 | entry |
| 2024-12-04 | 2024-12-05 | SPY | Sell | $606.66 | exit |
| 2024-12-26 | 2024-12-27 | SPY | Buy | $595.01 | entry |
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Risk warning
Past results do not predict future returns. Not investment advice.